Method of making multiple images from a migration imaged member

ABSTRACT

A migration imaged member is contacted with a transfer member wherein upon separation of said members, migration material from said migration imaged member is transferred in image configuration to said transfer member.

United States Patent [191 Lin [ 51 Sept. 17, 1974 METHOD OF MAKINGMULTIPLE IMAGES FROM A MIGRATION IMAGED MEMBER [75] Inventor: Luke C.Lin, Rochester, NY.

[73] Assignee: Xerox Corporation, Rochester, NY.

[22] Filed: Aug. 17, 1972 [21] Appl. No.: 281,615

Related US. Application Data [63] Continuation of Ser. No. 21,800, March23, 1970,

abandoned.

[52] US. Cl' 96/1.4, 96/1 PS, 96/1 M [51] Int. Cl. G03g 13/00, G03g13/14 [58] Field ofSearch 96/1.4,1 R, 1 PS, 1 M

[56] References Cited UNITED STATES PATENTS 3,520,681 7/1970 Goffe 96/13,565,612 2/1971 Clark 96/l.4 X 3,648,608 3/1972 Kaminstein 96/l.8 X3,664,834 5/1972 Amidon et a1. 96/l.4 3,708,288 1/1973 Lin 96/l.4

Primary Examiner-Ronald H. Smith Assistant Examiner-John R. MillerAttorney, Agent, or FirmJohn B. Mitchell; David C. Petre; James .1.Ralabate [57] ABSTRACT A migration imaged member is contacted with atransfer member wherein upon separation of said members, migrationmaterial from said migration imaged member is transferred in imageconfiguration to said transfer member.

12 Claims, 6 Drawing Figures PAIENIEBSEPWIBH 3.336.334

F76. 2A FIG; 2B

VENTOR. LU K C. LIN

BY l yvw (l? I A TTORNEV METHOD OF MAKING MULTIPLE IMAGES FROM AMIGRATION IMAGED MEMBER CROSS-REFERENCE TO RELATED APPLICATIONS This isa continuation, of application Ser. No. 21,800, filed'Mar. 23, 1970, nowabandoned.

BACKGROUND OF THE INVENTION This invention relates in general toimaging, and more specifically to a system employing contactingmigration imaged members with a transfer member wherein upon separationof said members, unmigrated material from said migration imaged memberhas transferred in image configuration to said transfer member.

Recently, a migration imaging system capable of producing high qualityimages of high density, continuous tone and high resolution has beendeveloped. Such migration imaging systems are disclosed in copendingapplication Ser. No. 837,780 and Ser. No. 837,591 both filed June 30,1969, which are hereby expressly incorporated herein by reference. In atypical embodiment of the new migration imaging system, there isprovided an imaging member comprising a substrate with a layer ofsoftenable material having dispersed therein migra tion material such aselectrically photosensitive particles. The member is imaged in thefollowing manner: a latent image is formed on the member, for example,by electrically charging the member and exposing it to a pattern ofactivating electromagnetic radiation such as light. The latent image isdeveloped by causing migration material in the softenable layer tomigrate imagewise toward the substrate when the member is developed asby softening the softenable layer.

One mode of development entails exposing the member to a solvent whichdissolves only the softenable layer. The migration material (typicallyparticles) which has been exposed to radiation migrates through thesoftenable layer as it is softened and dissolved, leaving an image ofmigrated particles corresponding to the radiation pattern of an originalon the substrate. The

material of the softenable layer is substantially completely washed awayby the solvent. The particle image may then be fixed to the substrate.For many preferred photosensitive particles, the image produced by theabove process is a negative of a positive original, i.e., particlesdeposit in image configuration corresponding to the radiation exposedareas. However, positive to positive systems are also possible byvarying imaging parameters. Those portions ofthe photosensitive materialwhich do not migrate to the substrate are washed away by the solventwith the softenable layer. As disclosed therein by other developingtechniques, the softenable layer may at least partially remain behind onthe supporting substrate with or without a relatively unmigrated patternof marking material complementary to said migrated material.

Softenable" as used here is intended to mean any material which can berendered more permeable to migration material migrating through itsbulk. Conventionally, changing permeability is accomplished bydissolving, melting and softening as by contact with heat, vapors,partial solvents and combinations thereof.

Fracturable layer or material as used herein, means any layer ormaterial which is capable of breaking up during development, therebypermitting portions of said layer to migrate toward the substrate inimage configuration. The fracturalble layer may be particulate,semi-continuous or continuous in various embodiments of the migrationimaging members.

Contiguous, for the purpose of this invention, is defined as in WebstersNew Collegiate Dictionary, Second Edition, 1960; In actual contact;touching; also, near, though not in contact; adjoining.

In certain methods of forming the latent image, nonphotosensitive orinert, fracturable layers and particulate material may be used to formimages, for example, wherein an electrostatic latent image is formed bya wide variety of methods including charging in image configurationthrough the use of a mask or stencil; first forming such a chargepattern on a separate photoconductive insulating layer according toconventional xerographic reproduction techniques and then transferringthis charge pattern to the imaging member by bringing the two layersinto very close proximity and utilizing breakdown techniques asdescribed, for exam ple, in Carlson U.S. Pat. No. 2,982,647 and WalkupU.S. Pat. Nos. 2,825,814 and 2,937,943. In addition, charge patternsconforming to selected shaped electrodes or combinations or electrodesmay be formed by the TESF discharge techniques as more fully describedin Schwertz U.S. Pat. Nos. 3,023,731 and 2,919,967 or by techniquesdescribed in Walkup U.S. Pat. No. 3,001,848 and 3,001,849 as well as byelectron beam recording techniques, for example, as described in GlennU.S. Pat. No. 3,113,179.

The characteristics of the images produced are dependent on such processsteps as charging, exposure and development as well as the particularcombination of process steps. High density, continuous tone and highresolution are some of the image characteristics possible. The image isgenerally characterized as a fixed or unfixed particulate image with orwithout a portion of the softenable layer and unmigrated portions of thelayer left on the imaged member.

A related but different invention to the present invention is describedin copending application Ser. No. 784,164, filed Dec. 16, 1968, now U.S.Pat. No. 3,741,757 wherein a migration imaged member is contacted with astripping sheet with sufficient adhesive contact between the transfersheet and the imaged member so that upon separation the imaged membersplits, typically at about middle thickness of the softenable layer tocreate simultaneously complementary positive and negative imagescorresponding to the relatively unmigrated and relatively migratedportions of the migration imaged member. In contrast, the instantinvention is directed not to splitting the imaging member at aboutmidway through the thickness of the softenable layer, but in removing aportion of one or the other of the relatively unmigrated or migratedparticles to a transfer member and typically preferably followed byrecontacting of the imaged member with a subsequent transfer member toremove: additional migration material from the same surface of themigration imaged member to produce multiple copies in the form of imagedtransfer members.

In this new migration imaging system, the advantageous transfer imagingsystem with multiple copy feature of this invention has been invented,utilizing migration imaged members as a master image.

SUMMARY OF THE INVENTION It is, therefore, an object of this inventionto provide a novel and advantageous transfer imaging system usingmigration imaging members as a master.

It is a still further object of this inventionto provide a migrationmember-transfer imaging system wherein a single migration imaged memberis split into a plurality of layers each on a different substrate.

Another object of this invention is to provide a dry method ofduplicating.

The foregoing objects and others are accomplished in accordance withthis invention by providing a migration imaged member which is contactedwith a transfer member and split upon separation of said member,whereupon a portion of migration material from said migration imagedmember is transferred in image configuration to said transfer member.The migration material remaining on the image is contacted with anothertransfer member and upon separation another portion of the migrationmaterial is transferred to the transfer member. The ability of an imagedmember to split into sucessive thin layers is due to the presence in thesoftenable layer 12 of a viscosity gradient. Such a gradient occurs insome cases by virtue of the development means employed to permitmigration and initial film splitting such as the use of a solvent vapor.In other cases the use of thermoplastic materials combined with theapplication of heat can achieve such a viscosity gradient. Temperaturesin the range of from about 150F to about 200F are usually sufficient toproduce a satisfactory viscosity gradient. When thermoplastic materialsof relatively low viscosity at room temperature are employed as thesoftenable layer, the application of heat is not required as airtemperature will provide the viscosity gradient. Also, the presence ofdispersed migration material in the film has been found to affectfavorably the ability of the softenable layer to split into thin layersto provide multiple copies.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of theinvention, as well as other objects and further features thereof,reference is made to the following detailed disclosure of this inventiontaken in conjunction with accompanying drawings wherein:

FIGS. 1A and 1B are partially schematic illustrations of a layeredconfiguration imaging member and an imaged layered configurationmigration imaging member respectively, according to this invention.

FIG. 2A is a partially schematic illustration of a binder migrationimaging member 18 wherein the migration material 13 is dispersedthroughout softenable layer 12 on substrate 11. FIG. 2B is a typicalbinder member 20 which has been migration imaged such that the migrationmaterial that was previously in portion 22 of softenable layer 12 hasmigrated into area 24 immediately beneath area 22 and closer to thesubstrate to create an image pattern of migration material in thebinder. Areas of the binder from which the migration material 13 hasmigrated can provide an image configuration in the upper surface of theimaged member 20.

FIG. 3A shows an imaged member of the type of FIG. 2B which has beensplit as taught in application Ser. No. 784,164 referred to above,substrate 32 being the stripping sheet and portion 34 corresponding tothe inverted upper portion of the imaged member 20 of FIG. 2B containingarea 22. FIG. 3B is the member of FIG. 3A with transfer member 36 havingbeen contacted with the top surface of member 30 and then having beenpartially separated to transfer to the under surface of transfer member36 a thin layer 38 from the surface of member 30. Layer 38 provides animage copy because portions 42 of layer 38 are relatively free ofmigration material in image configuration. When directly viewed from thelayer 38 side of transfer member 36, an image corresponding to the imagepattern in layer 30 but a reverse thereof will be observed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1A and2A, there are shown partially schematic drawings of examples ofembodiments of migration imaging members 8 and 18 comprising substrate11 and softenable layer 12 which contains contiguous to its uppersurface a layer of migration material 13. FIG. 1B shows a migrationimaging member of FIG. 1A after it has been migration imaged. Migrationmaterial portions 16 have migrated in depth in image configurationadjacent to the substrate 11 with relatively unmigrated portions 14 ofthe migration layer remaining contiguous to the surface of the imagedmember 10. Although migration material 13 is shown as a thin layer insoftenable layer 12, such migration material can also in a separatelayer coated over softenable layer 12 as a dispersion in softenablematerial of the same or different type as employed in softenable layer12. By employing such double layers, materials advantageous to producingcopies in accordance with this invention can be employed while lessadvantageous materials can be employed in softenable layer 12. Theimaged member can be employed directly in the method of this inventionor first split in half as described more fully below.

A more detailed description of substrate 11, softenable layer 12 andmigration materials and migration imaging methods may be found in thefirst two aforementioned copending applications incorporated herein byreference.

As disclosed in the first two copending applications mentioned above forboth the layer configuration and binder configuration imaging members, apreferred av erage particle size of the migration material is from about0.01 to about 2 microns to yield optimum resolution and highest densityimages. The preferred thickness range of softenable layer 12 is fromabout one-half to about 16 microns and optimally from about I to about 4microns.

As stated above when a migration imaged member of the type of FIG. 1B orFIG. 2B or a member comprising a split migration imaged member, forexample, illustrated in FIG. 3A is contacted with a transfer memberaccording to the invention, only a portion of the upper surface of themigration imaged member is found to be transferred to the transfermember leaving behind on the imaged member at least enough thickness ofsoftenable material to produce another transfer image, usually about sixmore images.

Transfer member 36 may be in the form of a web or sheet or any suitableform and the contacting surface of member 36 should be presented intopreferably nonslipping pressure contact with migration imaged member 30.A backing plate may optionally be used to regulate and control thepressure of the contact of transfer member 36 on imaged member 30. Aswill be seen, member 36 and substrate 11 may be opaque in variouscolors, translucent depending on the mode of operation and the ultimateuse of the web.

The transfer member 36 generally comprises a material having a surfaceeither capable of being rendered tacky as by the application of heat,solvents or the like or without the accompanying pressures or having asurface which is tacky such as an adhesively coated surface, forexample, pressure sensitive adhesive tapes. Member 36 is applied, withthe adhesive surface against migration imaged member 30, for example, bymeans of a roller. After application, the member 36 is separated fromimaged member 30.

Typical webs useful as transfer members 36 include polyethyleneterephthalate polyester film backed tapes, cellophane and acetate basedtapes such as Scotch brand Magic Transparent Tape No. 810 available fromthe 3M Company (all the foregoing being preferred for transparencyformation), commercially available masking tapes and similar adhesivewebs. Also, surfaces such as dye transfer paper, Cronar (Mylarovercoated with hydrophilic gelatin like layer) film from duPont andheat activated hot-melt adhesives are found to be suitable.

It is preferred that the thickness of member 36, if the images formed onmember 36 are to be used other than a light absorbing directly viewableimage, for example as a transparency, be kept relatively thin, on theorder of about 3 mils or less in order not to adversely affect imageresolution upon transmission of the image. For lower resolution films,of course, the films may be thicker up to about one-tenth inch thick. Ofcourse, it should be appreciated that the transfer member 36 to becontacted with migration imaged member 30 need not be a thin layer butmay comprise a solid member such as wood, plastic elements, metals andthe like, of course, which generally limits the resulting image carrieron this member to a directly viewable light absorbing image. Preferably,if this support base serving as transfer member 36 is not transparent,as when a thick metal member is employed, the image produced shouldcontrast with the surface for easier viewing.

In the pressing of transfer member 36 against the imaged member surface,pressures of from about 50 to 200 pounds per linear inch produce optimumresults.

The following Examples further specifically define the present migrationimaged member transfer imaging system of this invention. The parts andpercentages are by weight unless otherwise indicated. The Examples beloware intended to illustrate various preferred embodiments of thisinvention.

EXAMPLE I About 5 parts Staybelite Ester 10, a partially hydrogenatedrosin ester from Hercules Powder Co., is dissolved in about partscyclohexanone and about 75 parts toluene. Using a gravure roller, thesolution is then roll coated onto about a 3 mil Mylar polyester filmhaving a thin semi-transparent aluminum overcoating. The solutioncoating is applied so that when air dried for about 2 hours to allow forevaporation of the cyclohexanone and toluene solvents, about a 2 micronthick layer of Staybelite Ester 10 is formed on the aluminized Mylarsubstrate.

An overlayer coating dispersion is then prepared by mixing together adispersion made up of about 10 parts of x-form metal-free phthalocyaninephotoconductive particles, prepared as described in. Byrne U.S. Pat. No.3,357,989; about 4 A: parts of Picco-lastic resin A-25 a polystyreneresin and about 27 parts of Piccopale SF, a highly branch polyolefinboth available from Pennsylvania industrial Chemical Co., and about 64parts Isopar G (a long chain saturated aliphatic hydrocarbon liquid,boiling point 3l5-350F from Humble Oil and Chemical Co.). The dispersionis then coated onto the 2 micron layer of Staybelite Ester 10 with awire wound rod.

The member is imaged by uniformly electrostatically charging it to asurface potential of about +500 volts, exposing the charged member to apositive optical image including line copy with exposure in illuminatedareas of the member being about 0.3 f.c.s. from a tungsten lamp.

The member is developed by exposing it to the vapors of the solventtrichloroethane for about 10 seconds. An imaged member results as thephthalocyanine particles migrate in image-wise configuration toward thesubstrate through the Staybelite resin layer.

The imaged member is split according to the process described incopending application Ser. No. 784,164 referred to above. The top mostsplit off portion of the migration imaged member is transferred to atransfer member to produce a member similar to that illustrated in FIG.3A.

This member is then used as a master to produce seven additionaltransferred images by passing this member with the softenable layer incontact with seven successive paper transfer members through pressurerollers with a force of lbs/linear inch followed by stripping to form amirror reverse, but with the same sense image on each of the transfermembers.

EXAMPLE II] An imaging member is prepared by forming on an aluminizedpolyester film, available under the trade name Mylar from E. l. duPontde Nemours & Co., Inc., a softenable layer about 2 microns thick of aStaybelite ester 10 binder having zinc oxide particles of about 0.5microns in average diameter uniformly dispersed throughout theStaybelite ester in a dry weight ratio of zinc oxide to binder of about1 to 1. The member is uniformly electrostatically charged by means of acorona discharge device to a negative surface potential of about 240volts while in the dark and is then exposed to a light image having anintensity of about 200 footcandle seconds. The latent imaged member isdeveloped by exposing the member to vapors of a halogenated commerciallyavailable under the name Freon l 13 for about 10 seconds whereupon thezinc oxide migrates towards the film in the unexposed areas. The imagedmember is then split according to the process described in copendingapplication Ser. No. 784,164 referred to above providing a positiveimage on the upper half of the split image. The upper half of the splitimage is contacted with transparent cellophane tape available under thetrade name Scotch from the 3 M Company and passed between a pair ofpressure rollers one of which is heated. The imaged member is contactingthe heated roller which provides a viscosity gradient through the crosssection of the softenable layer such that a thin layer of the image istransferred to the tape.

This process is repeated six times to provide six images on successiveportions of the tape.

EXAMPLE Ill An imaging member is prepared by depositing about a 4 micronlayer of softenable material on a 3 mil Mylar film. The softenable layeris formed by coating a mixture of about 1 to 3 parts by volume stainlesssteel particles to Piccotex 100, a styrene homolog copolymer availablefrom the Pennsylvania Industrial Chemical Co., onto the film. Thestainless steel particles are in the range of from to 44 microns indiameter. The imaging member is subjected to an image shaped magneticfield and simultaneously to vapors of 1,1,1 trichloroethane for about 10seconds. As a result the stainless steel particles migrate in depthtoward the film and cluster at the edges of the magnetic field formingan outline of the magnetic image. The imaged member is subjected tosolvent vapor for the binder layer and split in accordance with theprocedure referred to in Example ll. The top half of the split image isthen used as a master to prepare five additional images by passing themaster in contact with separate sheets of Cronar, available from the E.l. duPont de Nemours & Co., lnc., which is heat activated prior tocontact with the master.

- The master in contact with the Cronar is passed between a pair ofpressure rollers exerting a pressure of about 150 pounds per linearinch. The roller contacting the master is heated to provide a viscositygradient across the softenable layer of the master. Five images are thusprepared by five successive transfers to Cronar sheets.

Although specific components and proportions have been stated in theabove description of preferred embodiments of the migration imagedmember-transfer imaging system of this invention, other suitablematerials, as listed herein, may be used with similar results andvarious degrees of quality. In addition, other materials which existpresently, or may be discovered, may

be added to materials used herein and variations may be made in thevarious processing steps to synergize, enhance or otherwise modify theproperties of this invention.

For example, with the choosing of the proper hydrophilic, hydrophobicnature of the particles relative to the binder therein, secondgeneration transfer members of this invention may be used aslithographic printing masters.

Also, advantageous enhancement of image contrast can be achieved byproper selection of migration material and transfer members especiallywith respect to their color. It will be understood that various otherchanges in the details, materials, steps and arrangements of parts,which have been herein described and illustrated in order to explain thenature of the invention, will occur to and may be made by those skilledin the art upon a reading of this disclosure and such changes areintended to be inclined within the principal and scope of thisinvention.

What is claimed is:

1. An imaging method for making multiple images from an originalcomprising the steps of:

a. providing a migration imaged member comprising a layer of softenablematerial containing a viscosity gradient and migration particlesdistributed in only one imaging configuration and at least some of saidmigration particles contiguous a free surface of said softenable layer,said migration imaged member having been made by splitting it from amigration imaged member which originally contained migration particlesdistributed in two image configurations;

b. contacting a transfer member against said free surface of said imagedmember; and

c. separating said transfer member and said imaged member whereby aportion of said imaged member including some but not all of saidmigration particles distributed in only one image configuration at saidfree surface is transferred to the transfer member to produce an imageon said transfer member.

2. An imaging method according to claim 1 wherein said migrationparticles are of an average particle size from about 0.01 to about 2microns and are dispersed in said softenable layer and wherein saidsoftenable layer is electrically insulating and is between from aboutone-half to about 16 microns thick.

3. An imaging method according to claim 1 wherein said softenablematerial comprises a a material selected from the group consisting ofpolystyrenes and aliphatic petroleum hydrocarbon resins.

4. An imaging method according to claim 1 wherein steps (b) and (c) arerepeated at least one additional time to transfer an image pattern to atleast one additional transfer member.

5. An imaging method according to claim 1 wherein the transfer member ispaper.

6. An imaging method according to claim 3 wherein the migrationparticles are metal free xphthalocyanine.

7. An imaging method according to claim 6 wherein the transfer memberand imaged member are passed between a pair of pressure rollers.

8. The imaging method of claim 7 wherein at least one of the rollers isheated.

9. The imaging method of claim 1 wherein the migration particlescomprise zinc oxide.

10. The imaging method of claim 1 wherein the transfer member is opaqueand has a tackifiable layer in contact with said free surface of saidimaged member.

11 An imaging method according to claim 1 wherein said imaged member isformed by forming an electrical latent image on an imaging membercomprising a layer of electrically insulating softenable material andmigration particles in said softenable material, said softenablematerial capable of having its resistance to migration of said migrationparticles decreased sufficiently to allow migration of said migrationmaterial through said softenable material and developing said electricallatent image by decreasing the resistance to migration of said migrationparticles through said softenable material at least sufficient to allowimagewise migration of migration particles at least in depth in thesoftenable layer.

12. The imaging method according to claim 1 wherein the contacting ofthe transfer member against the surface of the imaged member is acontact pressure from about 50 to 200 pounds per linear inch.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Paten No.3,836,364 Dated September 17, 1974 Invent0 Luke 0 Tin It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 25, change "or" second occurrence, to of Column 5, line4, after "translucent" insert or transparent Column 6, line 55, before"commercially" insert hydrocarbon Signed and sealed this 19th day ofNovember 1974.

(SEAL) Attest:

McCOY I-I. GIBSON JR, C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM PO-1050 (10-69) USCOMNPDC 76.p5g

9 1.5, GOVERNMENT PRINTNG UFFICE 1 I959 O-366-334

2. An imaging method according to claim 1 wherein said migrationparticles are of an average particle size from about 0.01 to about 2microns and are dispersed in said softenable layer and wherein saidsoftenable layer is electrically insulating and is between from aboutone-half to about 16 microns thick.
 3. An imaging method according toclaim 1 wherein said softenable material comprises a a material selectedfrom the group consisting of polystyrenes and aliphatic petroleumhydrocarbon resins.
 4. An imaging method according to claim 1 whereinsteps (b) and (c) are repeated at least one additional time to transferan image pattern to at least one additional transfer member.
 5. Animaging method according to claim 1 wherein the transfer member ispaper.
 6. An imaging method according to claim 3 wherein the migrationparticles are metal free x-phthalocyanine.
 7. An imaging methodaccording to claim 6 wherein the transfer member and imaged member arepassed between a pair of pressure rollers.
 8. The imaging method ofclaim 7 wherein at least one of the rollers is heated.
 9. The imagingmethod of claim 1 wherein the migration particles comprise zinc oxide.10. The imaging method of claim 1 wherein the transfer member is opaqueand has a tackifiable layer in contact with said free surface of saidimaged member. 11 An imaging method according to claim 1 wherein saidimaged member is formed by forming an electrical latent image on animaging member comprising a layer of electrically insulating softenablematerial and migration particles in said softenable material, saidsoftenable material capable of having its resistance to migration ofsaid migration particles decreased sufficiently to allow migration ofsaid migration material through said softenable material and developingsaid electrical latent image by decreasing the resistance to migrationof said migration particles through said softenable material at leastsufficient to allow imagewise migration of migration particles at leastin depth in the softenable layer.
 12. The imaging method according toclaim 1 wherein the contacting of the transfer member against thesurface of the imaged member is a contact pressure from about 50 to 200pounds per linear inch.